The news that China has become the first sovereign to establish a direct sales relationship with the U.S. Treasury (therefore cutting out the middleman and bypassing Wall Street ) raises a few interesting questions.

China can now bypass Wall Street when buying U.S. government debt and go straight to the U.S. Treasury, in what is the Treasury’s first-ever direct relationship with a foreign government, according to documents viewed by Reuters.

The relationship means the People’s Bank of China buys U.S. debt using a different method than any other central bank in the world.

The other central banks, including the Bank of Japan, which has a large appetite for Treasuries, place orders for U.S. debt with major Wall Street banks designated by the government as primary dealers. Those dealers then bid on their behalf at Treasury auctions.

China, which holds $1.17 trillion in U.S. Treasuries, still buys some Treasuries through primary dealers, but since June 2011, that route hasn’t been necessary.

The documents viewed by Reuters show the U.S. Treasury Department has given the People’s Bank of China a direct computer link to its auction system, which the Chinese first used to buy two-year notes in late June 2011.

The biggest Chinese outflows in U.S. Treasuries occurred in the months following the establishment of this relationship:

Which begs the question for some analysts — was China really selling? Or was China stealthily buying direct from the U.S. Treasury (unrecorded) and selling back into Wall Street (recorded)?

Well, according to the Treasury, the Treasury International Capital data seeks to record foreign holdings of U.S. securities, not just the flows, and given that the Treasury was the seller in these direct transactions (and so obviously was aware of them) there’s no reason to believe that they wouldn’t include any such direct outflows in the data. That suggests very strongly that yes, China really was selling.

And maybe the real reason that the Treasury offered China direct access (thus cutting out the middleman and offering China cheaper access than ever) was precisely because China was selling, and because the Treasury was concerned about the effect on rates, and wanted to give China some incentive to keep buying. As Jon Huntsman noted in a 2010 cable leaked by Wikileaks, the PBOC has felt pressured to keep buying, and as various PBOC officials have hinted in recent months, China is actively seeking to convert out of treasuries and into gold. And that makes sense — treasuries are yielding ever deeper negative real rates. People holding treasuries are losing their purchasing power. No wonder the treasury is willing to cut Wall Street out of the deal.

And it isn’t like the Treasury would have taken this move lightly — cutting Wall Street out of the equation is a slap in the face to Wall Street.

This raises a much more interesting question — now that the PBOC has effectively been upgraded to primary dealer status, would the Fed start buying treasuries directly from the PBOC in order to manage rates downward and prevent a spike in Treasury borrowing costs should China choose to quicken the pace of a future liquidation, potentially bursting the treasury bubble?